Renin Levels and Angiotensin II Responsiveness in Vasopressor-Dependent Hypotension.

OBJECTIVES: The relationship between renin levels, exposure to renin-angiotensin system (RAS) inhibitors, angiotensin II (ANGII) responsiveness, and outcome in patients with vasopressor-dependent vasodilatory hypotension is unknown. DESIGN: We conducted a single-center prospective observational study to explore whether recent RAS inhibitor exposure affected baseline renin levels, whether baseline renin levels predicted ANGII responsiveness, and whether renin levels at 24 hours were associated with clinical outcomes. SETTING: An academic ICU in Melbourne, VIC, Australia. PATIENTS: Forty critically ill adults who received ANGII as the primary agent for vasopressor-dependent vasodilatory hypotension who were included in the Acute Renal effects of Angiotensin II Management in Shock study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After multivariable adjustment, recent exposure to a RAS inhibitor was independently associated with a relative increase in baseline renin levels by 198% (95% CI, 36-552%). The peak amount of ANGII required to achieve target mean arterial pressure was independently associated with baseline renin level (increase by 46% per ten-fold increase; 95% CI, 8-98%). Higher renin levels at 24 hours after ANGII initiation were independently associated with fewer days alive and free of continuous renal replacement therapy (CRRT) (-7 d per ten-fold increase; 95% CI, -12 to -1). CONCLUSIONS: In patients with vasopressor-dependent vasodilatory hypotension, recent RAS inhibitor exposure was associated with higher baseline renin levels. Such higher renin levels were then associated with decreased ANGII responsiveness. Higher renin levels at 24 hours despite ANGII infusion were associated with fewer days alive and CRRT-free. These preliminary findings emphasize the importance of the RAS and the role of renin as a biomarker in patients with vasopressor-dependent vasodilatory hypotension.

Sodium Bicarbonate for Metabolic Acidosis in the ICU: Results of a Pilot Randomized Double-Blind Clinical Trial.

OBJECTIVES: To identify the best population, design of the intervention, and to assess between-group biochemical separation, in preparation for a future phase III trial. DESIGN: Investigator-initiated, parallel-group, pilot randomized double-blind trial. SETTING: Eight ICUs in Australia, New Zealand, and Japan, with participants recruited from April 2021 to August 2022. PATIENTS: Thirty patients greater than or equal to 18 years, within 48 hours of admission to the ICU, receiving a vasopressor, and with metabolic acidosis (pH < 7.30, base excess [BE] < -4 mEq/L, and Pa co2 < 45 mm Hg). INTERVENTIONS: Sodium bicarbonate or placebo (5% dextrose). MEASUREMENTS AND MAIN RESULT: The primary feasibility aim was to assess eligibility, recruitment rate, protocol compliance, and acid-base group separation. The primary clinical outcome was the number of hours alive and free of vasopressors on day 7. The recruitment rate and the enrollment-to-screening ratio were 1.9 patients per month and 0.13 patients, respectively. Time until BE correction (median difference, -45.86 [95% CI, -63.11 to -28.61] hr; p < 0.001) and pH correction (median difference, -10.69 [95% CI, -19.16 to -2.22] hr; p = 0.020) were shorter in the sodium bicarbonate group, and mean bicarbonate levels in the first 24 hours were higher (median difference, 6.50 [95% CI, 4.18 to 8.82] mmol/L; p < 0.001). Seven days after randomization, patients in the sodium bicarbonate and placebo group had a median of 132.2 (85.6-139.1) and 97.1 (69.3-132.4) hours alive and free of vasopressor, respectively (median difference, 35.07 [95% CI, -9.14 to 79.28]; p = 0.131). Recurrence of metabolic acidosis in the first 7 days of follow-up was lower in the sodium bicarbonate group (3 [20.0%] vs. 15 [100.0%]; p < 0.001). No adverse events were reported. CONCLUSIONS: The findings confirm the feasibility of a larger phase III sodium bicarbonate trial; eligibility criteria may require modification to facilitate recruitment.

Adults are just big kids: pediatric considerations for adult critical care nephrology.

PURPOSE OF REVIEW: In recent years, there has been growing attention to pediatric kidney health, especially pediatric acute kidney injury (AKI). However, there has been limited focus on the role of pediatric AKI on adult kidney health, specifically considerations for the critical care physician. RECENT FINDINGS: We summarize what is known in the field of pediatric AKI to inform adult medical care including factors throughout the early life course, including perinatal, neonatal, and pediatric exposures that impact survivor care later in adulthood. SUMMARY: The number of pediatric AKI survivors continues to increase, leading to a higher burden of chronic kidney disease and other long-term co-morbidities later in life. Adult medical providers should consider pediatric history and illnesses to inform the care they provide. Such knowledge may help internists, nephrologists, and intensivists alike to improve risk stratification, including a lower threshold for monitoring for AKI and kidney dysfunction in their patients.

Community-acquired versus hospital-acquired acute kidney injury at a large Australian metropolitan quaternary referral centre: incidence, associations and outcomes.

BACKGROUND: There is increasing global incidence of acute kidney injury (AKI) and significant short- and long-term impacts on patients. AIMS: To determine incidence and outcomes of community-acquired AKI (CA-AKI) and hospital-acquired AKI (HA-AKI) among inpatients in the Australian healthcare setting using modern health information systems. METHODS: A retrospective cohort study of adult patients admitted to a quaternary hospital in Melbourne, Australia, between 1 January 2018 and 31 December 2019 utilising an electronic data warehouse. Participants included adult patients admitted for >24 h who had more than one serum creatinine level recorded during admission. Kidney transplant and maintenance dialysis patients were excluded. Main outcomes measured included AKI, as classified by the Kidney Disease Improving Global Outcomes (KDIGO) criteria, hospital length of stay and 30-day mortality. RESULTS: A total of 6477 AKI episodes was identified across 43 791 admissions. Of all AKI episodes, 77% (n = 5011), 15% (n = 947) and 8% (n = 519) were KDIGO stage 1, 2 and 3 respectively. HA-AKI accounted for 55.9% episodes. Patients required intensive care unit admission in 22.7% (n = 1100) of CA-AKI and 19.3% (n = 935) of HA-AKI, compared with 7.5% (n = 2815) of patients with no AKI (P = 0.001). Patients with AKI were older with more co-morbidities, particularly chronic kidney disease (CKD). Length of stay was longer in CA-AKI (8.8 days) and HA-AKI (11.8 days) compared with admissions without AKI (4.9 days; P < 0.001). Thirty-day mortality was increased with CA-AKI (10.2%) and HA-AKI (12.8%) compared with no AKI (3.7%; P < 0.001). CONCLUSION: The incidence of AKI detected by the electronic data warehouse was higher than previously reported. Patients who experienced AKI had greater morbidity and mortality. CKD was an important risk factor for AKI in hospitalised patients.

Estimating baseline creatinine to detect acute kidney injury in patients with chronic kidney disease.

BACKGROUND: Accurately estimating baseline kidney function is essential for diagnosing acute kidney injury (AKI) in patients with chronic kidney disease (CKD). We developed and evaluated novel equations to estimate baseline creatinine in patients with AKI on CKD. METHODS: We retrospectively analysed 5649 adults with AKI out of 11 254 CKD patients, dividing them evenly into derivation and validation groups. Using quantiles regression, we created equations to estimate baseline creatinine, considering historical creatinine values, months since measurement, age, and sex from the derivation dataset. We assessed performance against back-estimation equations and unadjusted historical creatinine values using the validation dataset. RESULTS: The optimal equation adjusted the most recent creatinine value for time since measurement and sex. Estimates closely matched the actual baseline at AKI onset, with median (95% confidence interval) differences of just 0.9% (-0.8% to 2.1%) and 0.6% (-1.6% to 3.9%) when the most recent value was within 6 months to 30 days and 2 years to 6 months before AKI onset, respectively. The equation improved AKI event reclassification by an additional 2.5% (2.0% to 3.0%) compared to the unadjusted most recent creatinine value and 7.3% (6.2% to 8.4%) compared to the CKD-EPI 2021 back-estimation equation. CONCLUSION: Creatinine levels drift in patients with CKD, causing false positives in AKI detection without adjustment. Our novel equation adjusts the most recent creatinine value for drift over time. It provides more accurate baseline creatinine estimation in patients with suspected AKI on CKD, which reduces false-positive AKI detection, improving patient care and management.

Features, risk factors, and outcomes of older internal medicine patients triggering a medical emergency team call.

BACKGROUND: Information about the epidemiology of older Internal Medicine patients receiving medical emergency team (MET) calls is limited. We assessed the prevalence, characteristics, risk factors, and outcomes of this vulnerable group. METHODS: Internal Medicine patients aged >75 years who were admitted via the Emergency Department to a tertiary hospital between January 2015 to December 2018 and who activated a MET call were compared to patients without MET call activation during the same time period. Outcome measures included management post-MET call, Intensive Care Unit (ICU) admission rates, discharge disposition, length of hospital stays (LOS), and in-patient mortality. RESULTS: There were 10,803 Internal Medical admissions involving 10,423 patients; median age 85 (IQR 81-89) years. Of these, 995 (10%) patients received at least one MET call. MET call patients had greater physiological instability in the Emergency Department and higher median Charlson comorbidity index values (2, IQR 1-3 vs. 1, IQR 0-2; p < .0001) than non-MET call patients. Overall, 10% of MET call patients were admitted to ICU. MET patients had a longer median length of stay (9 [IQR 5-14] vs. 4 days [IQR 2-7]; p < .001) and higher in-hospital mortality (29% vs. 7%; p < .001). However, mortality of MET call patients without treatment limitations was 48/357 (13%). CONCLUSION: One in ten Internal Medicine patients aged >75 years and admitted via ED had a MET call. Physiological instability in ED and comorbidities were key risk factors. Mortality in MET patients approached 30%. These data can help predict at-risk patients for improving goals of care and pre-MET interventions.

Practice patterns and predictors of outpatient care following acute kidney injury in an Australian healthcare setting.

BACKGROUND: Survivors of acute kidney injury (AKI) are at increased risk of major adverse kidney events and international guidelines recommend individuals be evaluated 3 months following AKI. AIM: We describe practice patterns and predictors of post-AKI care in an Australian tertiary hospital. METHODS: A retrospective analysis was undertaken of adults with AKI (defined by KDIGO criteria) admitted to a single centre between 2012 and 2016. The primary outcome was outpatient nephrology review at 3 months. Secondary outcomes included inpatient nephrology review, and outpatient serum creatinine and urinary protein measurements. Data were analysed using multivariable logistic and competing risk regression. RESULTS: Only 117 of 2111 (6%) patients with AKI were reviewed by a nephrologist at 3 months. Reviewed patients were more likely to have a higher discharge serum creatinine (odds ratio (OR) 1.20 per 10 µmol/L increase; 95% confidence interval (CI) 1.16-1.25) or a history of peripheral vascular disease (OR 1.77; 95% CI 1.00-3.14). They were less likely to be older (OR 0.66 per decade; 95% CI 0.57-0.76) or to have a history of liver (OR 0.47; 95% CI 0.26-0.87) or ischaemic heart (OR 0.50; 95% CI 0.27-0.94) disease. AKI stage did not predict follow up. The median time from discharge to outpatient serum creatinine testing was 12 days (interquartile range 4-47) and proteinuria was measured in 538 (25%) patients. CONCLUSIONS: A minority of admitted AKI patients receive recommended post-AKI care. Studies in other Australian institutions are required to confirm or refute these concerning findings.

Estimating baseline kidney function in hospitalized adults with acute kidney injury.

AIM: Baseline serum creatinine values are required to diagnose acute kidney injury but are often unavailable. We evaluated four conventional equations to estimate creatinine. We then developed and validated a new equation corrected by age and gender. METHODS: We retrospectively examined adults who, at first hospital admission, had available baseline creatinine data and developed acute kidney injury ≥24 h after admission. We split the study population: 50% (derivation) to develop a new linear equation and 50% (validation) to compare against conventional equations for bias, precision, and accuracy. We stratified analyses by age and gender. RESULTS: We studied 3139 hospitalized adults (58% male, median age 71). Conventional equations performed poorly in bias and accuracy in patients aged <60 or ≥75 (68% of the study population). The new linear equation had less bias and more accuracy. There were no clinically significant differences in precision. The median (95% confidence interval) difference in creatinine values estimated via the new equation minus measured baselines was 0.9 (-3.0, 5.9) and -0.5 (-7.0, 3.7) µmol/L in female patients 18-60 and 75-100, and -1.5 (-4.2, 2.2) and -7.8 (-12.7, -3.6) µmol/L in male patients 18-60 and 75-100, respectively. The new equation improved reclassification of KDIGO AKI stages compared to the MDRD II equation by 5.0%. CONCLUSION: Equations adjusted for age and gender are less biased and more accurate than unadjusted equations. Our new equation performed well in terms of bias, precision, accuracy, and reclassification.

Clinical impact of genomic testing in patients with suspected monogenic kidney disease.

PURPOSE: To determine the diagnostic yield and clinical impact of exome sequencing (ES) in patients with suspected monogenic kidney disease. METHODS: We performed clinically accredited singleton ES in a prospectively ascertained cohort of 204 patients assessed in multidisciplinary renal genetics clinics at four tertiary hospitals in Melbourne, Australia. RESULTS: ES identified a molecular diagnosis in 80 (39%) patients, encompassing 35 distinct genetic disorders. Younger age at presentation was independently associated with an ES diagnosis (p < 0.001). Of those diagnosed, 31/80 (39%) had a change in their clinical diagnosis. ES diagnosis was considered to have contributed to management in 47/80 (59%), including negating the need for diagnostic renal biopsy in 10/80 (13%), changing surveillance in 35/80 (44%), and changing the treatment plan in 16/80 (20%). In cases with no change to management in the proband, the ES result had implications for the management of family members in 26/33 (79%). Cascade testing was subsequently offered to 40/80 families (50%). CONCLUSION: In this pragmatic pediatric and adult cohort with suspected monogenic kidney disease, ES had high diagnostic and clinical utility. Our findings, including predictors of positive diagnosis, can be used to guide clinical practice and health service design.

Hemodialysis Use and Practice Patterns: An International Survey Study.

RATIONALE & OBJECTIVE: Hemodialysis (HD) is the most common form of kidney replacement therapy. This study aimed to examine the use, availability, accessibility, affordability, and quality of HD care worldwide. STUDY DESIGN: A cross-sectional survey. SETTING & PARTICIPANTS: Stakeholders (clinicians, policy makers, and consumer representatives) in 182 countries were convened by the International Society of Nephrology from July to September 2018. OUTCOMES: Use, availability, accessibility, affordability, and quality of HD care. ANALYTICAL APPROACH: Descriptive statistics. RESULTS: Overall, representatives from 160 (88%) countries participated. Median country-specific use of maintenance HD was 298.4 (IQR, 80.5-599.4) per million population (pmp). Global median HD use among incident patients with kidney failure was 98.0 (IQR, 81.5-140.8) pmp and median number of HD centers was 4.5 (IQR, 1.2-9.9) pmp. Adequate HD services (3-4 hours 3 times weekly) were generally available in 27% of low-income countries. Home HD was generally available in 36% of high-income countries. 32% of countries performed monitoring of patient-reported outcomes; 61%, monitoring of small-solute clearance; 60%, monitoring of bone mineral markers; 51%, monitoring of technique survival; and 60%, monitoring of patient survival. At initiation of maintenance dialysis, only 5% of countries used an arteriovenous access in almost all patients. Vascular access education was suboptimal, funding for vascular access procedures was not uniform, and copayments were greater in countries with lower levels of income. Patients in 23% of the low-income countries had to pay >75% of HD costs compared with patients in only 4% of high-income countries. LIMITATIONS: A cross-sectional survey with possibility of response bias, social desirability bias, and limited data collection preventing in-depth analysis. CONCLUSIONS: In summary, findings reveal substantial variations in global HD use, availability, accessibility, quality, and affordability worldwide, with the lowest use evident in low- and lower-middle-income countries.

Peritoneal Dialysis Use and Practice Patterns: An International Survey Study.

RATIONALE & OBJECTIVE: Approximately 11% of people with kidney failure worldwide are treated with peritoneal dialysis (PD). This study examined PD use and practice patterns across the globe. STUDY DESIGN: A cross-sectional survey. SETTING & PARTICIPANTS: Stakeholders including clinicians, policy makers, and patient representatives in 182 countries convened by the International Society of Nephrology between July and September 2018. OUTCOMES: PD use, availability, accessibility, affordability, delivery, and reporting of quality outcome measures. ANALYTICAL APPROACH: Descriptive statistics. RESULTS: Responses were received from 88% (n=160) of countries and there were 313 participants (257 nephrologists [82%], 22 non-nephrologist physicians [7%], 6 other health professionals [2%], 17 administrators/policy makers/civil servants [5%], and 11 others [4%]). 85% (n=156) of countries responded to questions about PD. Median PD use was 38.1 per million population. PD was not available in 30 of the 156 (19%) countries responding to PD-related questions, particularly in countries in Africa (20/41) and low-income countries (15/22). In 69% of countries, PD was the initial dialysis modality for≤10% of patients with newly diagnosed kidney failure. Patients receiving PD were expected to pay 1% to 25% of treatment costs, and higher (>75%) copayments (out-of-pocket expenses incurred by patients) were more common in South Asia and low-income countries. Average exchange volumes were adequate (defined as 3-4 exchanges per day or the equivalent for automated PD) in 72% of countries. PD quality outcome monitoring and reporting were variable. Most countries did not measure patient-reported PD outcomes. LIMITATIONS: Low responses from policy makers; limited ability to provide more in-depth explanations underpinning outcomes from each country due to lack of granular data; lack of objective data. CONCLUSIONS: Large inter- and intraregional disparities exist in PD availability, accessibility, affordability, delivery, and reporting of quality outcome measures around the world, with the greatest gaps observed in Africa and South Asia.

Epidemiology and Outcomes of Acute Kidney Diseases: A Comparative Analysis.

INTRODUCTION: Acute kidney diseases and disorders (AKD) encompass acute kidney injury (AKI) and subacute or persistent alterations in kidney function that occur after an initiating event. Unlike AKI, accurate estimates of the incidence and prognosis of AKD are not available and its clinical significance is uncertain. METHODS: We studied the epidemiology and long-term outcome of AKD (as defined by the KDIGO criteria), with or without AKI, in a retrospective cohort of adults hospitalized at a single centre for >24 h between 2012 and 2016 who had a baseline eGFR ≥60 mL/min/1.73 m2 and were alive at 30 days. In patients for whom follow-up data were available, the risks of major adverse kidney events (MAKEs), CKD, kidney failure, and death were examined by Cox and competing risk regression analyses. RESULTS: Among 62,977 patients, 906 (1%) had AKD with AKI and 485 (1%) had AKD without AKI. Follow-up data were available for 36,118 patients. In this cohort, compared to no kidney disease, AKD with AKI was associated with a higher risk of MAKEs (40.25 per 100 person-years; hazard ratio [HR] 2.51, 95% confidence interval [CI] 2.16-2.91), CKD (27.84 per 100 person-years); subhazard ratio [SHR] 3.18, 95% CI 2.60-3.89), kidney failure (0.56 per 100 person-years; SHR 24.84, 95% CI 5.93-104.03), and death (14.86 per 100 person-years; HR 1.52, 95% CI 1.20-1.92). Patients who had AKD without AKI also had a higher risk of MAKEs (36.21 per 100 person-years; HR 2.26, 95% CI 1.89-2.70), CKD (22.94 per 100 person-years; SHR 2.69, 95% CI 2.11-3.43), kidney failure (0.28 per 100 person-years; SHR 12.63, 95% CI 1.48-107.64), and death (14.86 per 100 person-years; HR 1.57, 95% CI 1.19-2.07). MAKEs after AKD were driven by CKD, especially in the first 3 months. CONCLUSIONS: These findings establish the burden and poor prognosis of AKD and support prioritisation of clinical initiatives and research strategies to mitigate such risk.

Availability, coverage, and scope of health information systems for kidney care across world countries and regions.

BACKGROUND: Health information systems (HIS) are fundamental tools for the surveillance of health services, estimation of disease burden and prioritization of health resources. Several gaps in the availability of HIS for kidney disease were highlighted by the first iteration of the Global Kidney Health Atlas. METHODS: As part of its second iteration, the International Society of Nephrology conducted a cross-sectional global survey between July and October 2018 to explore the coverage and scope of HIS for kidney disease, with a focus on kidney replacement therapy (KRT). RESULTS: Out of a total of 182 invited countries, 154 countries responded to questions on HIS (85% response rate). KRT registries were available in almost all high-income countries, but few low-income countries, while registries for non-dialysis chronic kidney disease (CKD) or acute kidney injury (AKI) were rare. Registries in high-income countries tended to be national, in contrast to registries in low-income countries, which often operated at local or regional levels. Although cause of end-stage kidney disease, modality of KRT and source of kidney transplant donors were frequently reported, few countries collected data on patient-reported outcome measures and only half of low-income countries recorded process-based measures. Almost no countries had programs to detect AKI and practices to identify CKD-targeted individuals with diabetes, hypertension and cardiovascular disease, rather than members of high-risk ethnic groups. CONCLUSIONS: These findings confirm significant heterogeneity in the global availability of HIS for kidney disease and highlight important gaps in their coverage and scope, especially in low-income countries and across the domains of AKI, non-dialysis CKD, patient-reported outcomes, process-based measures and quality indicators for KRT service delivery.

Inpatient and outpatient nephrology management of critically ill patients with acute kidney injury.

INTRODUCTION: Acute kidney injury (AKI) during critical illness increases the risk of subsequent chronic kidney disease. Guidelines recommend inpatient nephrology assessment and review at 3 months. OBJECTIVES: To quantify the prevalence and predictors of inpatient and outpatient nephrology follow-up of AKI patients admitted to critical care areas within a tertiary hospital. METHODS: Retrospective study of all critically ill adults with AKI between January 1, 2012 and December 31, 2016 with a baseline estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m2 and alive and independent of renal replacement therapy for 30 days after hospital discharge. We used logistic regression models to examine the primary outcome of nephrology review at 3 months. Secondary outcomes included inpatient nephrology review, renal recovery at discharge and the development of a major adverse kidney event (MAKE) at 1 year. RESULTS: Of 702 critically ill patients with AKI (mean age 66 years, 64% male, baseline eGFR 78 mL/min/1.73 m2 ), 43 patients (6%) received nephrology follow-up at 3 months and 63 patients (9%) at 1 year. Nephrology follow-up occurred more frequently in patients with a higher baseline creatinine, a higher discharge creatinine and greater severity of AKI. Seventy patients (10%) underwent inpatient nephrology review. Overall, 414 (59%) had recovery of renal function by the time of discharge and 239 (34%) developed a MAKE at 12 months. CONCLUSION: Inpatient and outpatient nephrology follow-up of AKI patients after admission to a critical care area was uncommon although one-third developed a MAKE. These findings provide the rationale for controlled studies of nephrology follow-up.

Variability and trends over time and across centres in haemodialysis weekly duration in Australia and New Zealand.

AIM: Haemodialysis treatment prescription varies widely internationally. This study explored patient- and centre-level characteristics associated with weekly haemodialysis hours. METHODS: Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry data were analysed. Characteristics associated with weekly duration were evaluated using mixed-effects linear regression models with patient- and centre-level covariates as fixed effects, and dialysis centre and state as random effects using the 2017 prevalent in-centre haemodialysis (ICHD) and home haemodialysis (HHD) cohorts. Evaluation of patterns of weekly duration over time analysed the 2000 to 2017 incident ICHD and HHD cohorts. RESULTS: Overall, 12 494 ICHD and 1493 HHD prevalent patients in 2017 were included. Median weekly treatment duration was 13.5 (interquartile range [IQR] 12-15) hours for ICHD and 16 (IQR 15-20) hours for HHD. Male sex, younger age, higher body mass index, arteriovenous fistula/graft use, Aboriginal and Torres Strait Islander ethnicity and longer dialysis vintage were associated with longer weekly duration for both ICHD and HHD. No centre characteristics were associated with duration. Variability in duration across centres was very limited in ICHD compared with HHD, with variation in HHD being associated with state. Duration did not vary significantly over time for ICHD, whereas longer weekly HHD treatments were reported between 2006 and 2012 compared with before and after this period. CONCLUSION: This study in the Australian and New Zealand haemodialysis population showed that weekly duration was primarily associated with patient characteristics. No centre effect was demonstrated. Practice patterns seemed to differ across states/countries, with more variability in HHD than ICHD.

Volume management in haemodialysis patients.

PURPOSE OF REVIEW: Accumulating evidence supports the important contribution of volume-related metrics to morbidity and mortality in patients receiving chronic haemodialysis. The purpose of this review is to summarize recent advances in the understanding and management of volume status in this high-risk group. RECENT FINDINGS: Delivery of optimal volume management involves three key components: accurate estimation of volume status, correction of extracellular fluid overload and prevention of intradialytic instability. The lack of a gold standard for assessing volume status makes accurate estimation difficult to achieve; clinical examination has insufficient sensitivity and specificity, while tools to assist in the objective measurement of extracellular fluid volume require further validation. Hypervolemia is common in patients on chronic haemodialysis and substantially increases the risk of morbidity and mortality. Rapid correction of hypervolemia should be avoided due to the risk of precipitating intradialytic hypotension and hypoperfusion of vital end-organs, including the heart, brain, liver, gut and kidneys. Evidence-based interventions to aid in normalizing extracellular fluid volume are urgently needed; several targeted strategies are currently being evaluated. Many centres have successfully implemented local protocols and programmes to enhance volume management. SUMMARY: Achieving normal volume status is a fundamental goal of haemodialysis. Novel methods of assessing and restoring extracellular fluid volume while maintaining intradialytic stability are currently undergoing evaluation. Implementation of volume-related strategies into clinical practice is feasible and may improve patient outcome.

Effect of centre- and patient-related factors on uptake of haemodiafiltration in Australia and New Zealand: A cohort study using ANZDATA.

BACKGROUND: The use of haemodiafiltration (HDF) for the management of patients with end-stage kidney failure is increasing worldwide. Factors associated with HDF use have not been studied and may vary in different countries and jurisdictions. The aim of this study was to document the pattern of increase and variability in uptake of HDF in Australia and New Zealand, and to describe patient- and centre-related factors associated with its use. METHODS: Using the Australian and New Zealand Dialysis and Transplant Registry, all incident patients commencing haemodialysis (HD) between 2000 and 2014 were included. The primary outcome was HDF commencement over time, which was evaluated using multivariable logistic regression stratified by country. RESULTS: Of 27 433 patients starting HD, 3339 (14.4%) of 23 194 patients in Australia and 810 (19.1%) of 4239 in New Zealand received HDF. HDF uptake increased over time in both countries but was more rapid in New Zealand than Australia. In Australia, HDF use was more likely in males (odds ratio (OR) 1.13, 95% confidence interval (CI) = 1.03-1.24, P = 0.009) and less likely with older age (reference <40 years; 40-54 years OR = 0.85; 95% CI = 0.72-0.99; 55-69 years OR = 0.79; 95% CI = 0.67-0.91; >70 years OR = 0.48; 95% CI = 0.41-0.56); higher body mass index (body mass index (BMI) < 18.5 kg/m2 OR = 0.62; 95% CI = 0.46-0.84; 18.5-29.9 kg/m2 reference; >30 kg/m2 OR = 1.46; 95% CI = 1.33-1.61), chronic lung disease (OR = 0.84; 95% CI = 0.76-0.94; P < 0.001), cerebrovascular disease (OR = 0.76; 95% CI = 0.67-0.85; P < 0.001) and peripheral vascular disease (OR = 0.77; 95% CI = 0.70-0.85; P < 0.001). No association was identified with race. In New Zealand, HDF use was more likely in Maori and Pacific Islanders (OR = 1.32; 95% CI = 1.05-1.66) and Asians (OR = 1.75; 95% CI = 1.15-2.68) compared to Caucasians, and less likely in males (OR = 0.76; 95% CI = 0.62-0.94; P = 0.01). No association was identified with BMI or co-morbidities. In both countries, centres with a higher ratio of HD to peritoneal dialysis (PD) were more likely to prescribe HDF. Larger Australian centres were more likely to prescribe HDF (36-147 new patients/year OR = 26.75, 95% CI = 18.54-38.59; 17-35/year OR = 7.51, 95% CI = 5.35-10.55; 7-16/year OR = 3.00; 95% CI = 2.19-4.13; ≤6/year reference). CONCLUSION: Haemodiafiltration uptake is increasing, variable and associated with both patient and centre characteristics. Centre characteristics not explicitly captured elsewhere explained 36% of variability in HDF uptake in Australia and 48% in New Zealand.

Long-term risk of adverse outcomes after acute kidney injury: a systematic review and meta-analysis of cohort studies using consensus definitions of exposure.

Reliable estimates of the long-term outcomes of acute kidney injury (AKI) are needed to inform clinical practice and guide allocation of health care resources. This systematic review and meta-analysis aimed to quantify the association between AKI and chronic kidney disease (CKD), end-stage kidney disease (ESKD), and death. Systematic searches were performed through EMBASE, MEDLINE, and grey literature sources to identify cohort studies in hospitalized adults that used standardized definitions for AKI, included a non-exposed comparator, and followed patients for at least 1 year. Risk of bias was assessed by the Newcastle-Ottawa Scale. Random effects meta-analyses were performed to pool risk estimates; subgroup, sensitivity, and meta-regression analyses were used to investigate heterogeneity. Of 4973 citations, 82 studies (comprising 2,017,437 participants) were eligible for inclusion. Common sources of bias included incomplete reporting of outcome data, missing biochemical values, and inadequate adjustment for confounders. Individuals with AKI were at increased risk of new or progressive CKD (HR 2.67, 95% CI 1.99-3.58; 17.76 versus 7.59 cases per 100 person-years), ESKD (HR 4.81, 95% CI 3.04-7.62; 0.47 versus 0.08 cases per 100 person-years), and death (HR 1.80, 95% CI 1.61-2.02; 13.19 versus 7.26 deaths per 100 person-years). A gradient of risk across increasing AKI stages was demonstrated for all outcomes. For mortality, the magnitude of risk was also modified by clinical setting, baseline kidney function, diabetes, and coronary heart disease. These findings establish the poor long-term outcomes of AKI while highlighting the importance of injury severity and clinical setting in the estimation of risk.

Patient survival on haemodiafiltration and haemodialysis: a cohort study using the Australia and New Zealand Dialysis and Transplant Registry.

Background: It is unclear if haemodiafiltration improves patient survival compared with standard haemodialysis. Observational studies have tended to show benefit with haemodiafiltration, while meta-analyses have not provided definitive proof of superiority. Methods: Using data from the Australia and New Zealand Dialysis and Transplant Registry, this binational inception cohort study compared all adult patients who commenced haemodialysis in Australia and New Zealand between 2000 and 2014. The primary outcome was all-cause mortality. Cardiovascular mortality was the secondary outcome. Outcomes were measured from the first haemodialysis treatment and were examined using multivariable Cox regression analyses. Patients were censored at permanent discontinuation of haemodialysis or at 31 December 2014. Analyses were stratified by country. Results: The study included 26 961 patients (4110 haemodiafiltration, 22 851 standard haemodialysis; 22 774 Australia, 4187 New Zealand) with a median follow-up of 5.31 (interquartile range 2.87-8.36) years. Median age was 62 years, 61% were male, 71% were Caucasian. Compared with standard haemodialysis, haemodiafiltration was associated with a significantly lower risk of all-cause mortality [adjusted hazard ratio (HR) for Australia 0.79, 95% confidence interval (95% CI) 0.72-0.87; adjusted HR for New Zealand 0.88, 95% CI 0.78-1.00]. In Australian patients, there was also an association between haemodiafiltration and reduced cardiovascular mortality (adjusted HR 0.78, 95% CI 0.64-0.95). Conclusion: Haemodiafiltration was associated with superior survival across patient subgroups of age, sex and comorbidity.